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This level measuring instrument which operates with microwaves, has a radiation characteristic with a pronounced forward lobe and can be used to transmit and/or receive microwaves with a large frequency bandwidth. A housing section is designed as a waveguide short-circuited at one side and one end b

This level measuring instrument which operates with microwaves, has a radiation characteristic with a pronounced forward lobe and can be used to transmit and/or receive microwaves with a large frequency bandwidth. A housing section is designed as a waveguide short-circuited at one side and one end by a rear wall, and is virtually completely filled with an insert made of a dielectric. An exciter element, projects into the housing section and is connected to a microwave source. An antenna adjoins the housing section, for transmitting and/or receiving microwaves. A gap is arranged in the insert between the exciter element and the antenna. The gap forms a filter which is essentially non-transparent to higher modes of the waveguide.

대표청구항 ▼

1. A level measuring instrument, comprisingan exciter element that excites microwaves; an antenna that transmits microwaves received from the exciter element; a waveguide between the exciter element and the antenna that guides microwaves between the exciter element and the antenna, the waveguide def

1. A level measuring instrument, comprisingan exciter element that excites microwaves; an antenna that transmits microwaves received from the exciter element; a waveguide between the exciter element and the antenna that guides microwaves between the exciter element and the antenna, the waveguide defining a longitudinal axis between the exciter element and the antenna; and a dielectric insert positioned in the waveguide between the exciter element and the antenna, the dielectric insert comprising dielectric material and a longitudinal gap in the dielectric material of the dielectric insert that lies along the longitudinal axis, the longitudinal gap sized to pass to the antenna a fundamental mode portion of the microwaves received from the exciter element, and filter from the antenna a higher mode portion of the microwaves received from the exciter element.